Twister device for producing crimped filamentary yarns

ABSTRACT

A twister device for producing crimped yarns comprising a turbine blade rotary member mounted in the casing. The turbine blade rotary member includes a twister pin for an introduced filamentary yarn disposed in interior of a hollow shaft thereof and is rotated at a high speed in the casing when compressed air is applied onto blades formed on the circumference the hollow shaft.

United States Patent [191 [111 3,927,517

Kimoto [45] Dec. 23, 1975 [54] TWISTER DEVICE FOR PRODUCING 3,392,519 7/1968 Parker 57/7745 CRIMPED FILAMENTARY YARNS 3,759,025 9/1973 Takai et a]. 57/77.45

Primary Examiner-Donald E. Watkins Attorney, Agent, or Firm-Whittemore, Hulbert & Belknap 57 ABSTRACT A twister device for producing crimped yarns comprising a turbine blade rotary member mounted in the casing. The turbine blade rotary member includes a twister pin for an introduced filamentary yarn disposed in interior of a hollow shaft thereof and is rotated at a high speed in the casing when compressed air is applied onto blades formed on the circumference the hollow shaft.

5 Claims, 4 Drawing Figures US. Patent Dec.23, 1975 Sheet10f2 3,927,517

Sheet 2 of 2 3,927,517

US. Patent Dec. 23, 1975 TWISTER DEVICE FOR PRODUCING CRIMPED FILAMENTARY YARNS DESCRIPTION OF PRIOR ART crimps in filamentary yarns. According to this method,- strong twists are imparted to a filamentary yarn by the false twister device while the filamentary yarn is passing through the twister device, and the filamentary yarn is thermally set in the so twisted state and the thermally set yarn is simultaneously untwisted and wound on a package. Accordingly, the bent state in individual filaments formed by the twister device and set by the heat treatment is left as a complicated spiral form even after the untwisting.

As another method forproducing crimped filamentary yarns, there can be mentioned a method in which a bundle of filamentary yarns is twisted in advance along a prescribed distance and the bundle is travelled while the twisted portion is being heated.

The former false twisting method, however, has such a fatal structural defect that rollers for contact-driving a spindle and bearings of driving rollers are readily worn and because of abrasion of these members the equipment costs and maintenance expenses become great, though the rotation number can be enhanced to some extent by employing a spindle of a specific structure. Owing to the above defect, the rotation number is limited in ordinary spindles and it is generally in a range of about 350,000 to 450,000 rotations per minute.

The manufacturing rate of crimped filamentary yarns is determined by the rotation number of the spindle, and the number of twists necessary for imparting crimps to ayarn is, for example, 3000 to 3500 twists per meter in the case of a 70-denier yarn, though this twist number differs to some extent depending on the size of the yarn. Accordingly, a yarn speed required for producing crimped yarns is about 100 to about 120 m/min.

In this false twisting method, in the case of ordinary spindles customarily used in the art, a twister pin is heated owing to friction by driving rollers and because a heated yarn (about 100C.) passes through the twister pin, it is further heated and its temperature becomes almost as high as the yarn temperature. If the temperature of this twister pin acting as the twisting or untwisting point is higher than the second transition point of the fiber to be processed, the crimp fastness and bulkiness are reduced in the resulting crimped yarn.

In the latter method, enhancement of the processing speed can be expected to some extent because a rotary member such as a spindle is not employed. However, since it is necessary to separate forcibly two or more filamentary yarns at the preliminarily twisted portion, such undesired phenomena as yarn breakages, formation of fluffs and bad crimp forms owing to excessive tension applied at the separation of yarns are brought about. Further, since a bundle of two or more filamentary yarns is twisted, the critical number of twists should naturally be reduced and hence, the resulting crimped yarn is inferior in the bulkiness.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a view illustrating an apparatus for producing crimped filamentary yarns which includes the twister device of the present invention.

FIG. 2 is a partially cut-out plan view showing one embodiment of the twister device of the present invention.

FIG. 3 is a sectional front view taken along the line llIIII in FIG. 2.

FIG. 4 is a cross-sectional plan view taken along the line IV-IV in FIG. 3.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a twister device for producing crimped filamentary yarns, in which the operation speed can be greatly enhanced by provision of a turbine blade type rotary member having a twister pm. I

According to the present invention, the processing operation can be performed at such a high rate as 800,000 rotations per minute by provision of a turbine blade type rotary member having a twister pin, and crimped yarns excellent in the bulkiness can easily be prepared at a highly improved manufacturing rate.

An embodiment of the twister device of the present invention will now be described by reference to the accompanying drawings.

As is shown in FIG. 1, the twister device 1 of the present invention is disposed between a heater 2 and an apron type take-up roller 6 to twist and untwist an unprocessed filamentary yarn 3. In FIG. 1, the unprocessed filamentary yarn 3 wound on a bobbin 4 is fed to the heater 2 through a first guide 5 by means of an apron type feed roller 7. In the heater 2, the unprocessed filamentary yarn 3 is heated at a temperature ranging from room temperature to about 200C. (it is preferred that the yarn is heated at about 180C. in the case of polyamide fibers and at about 230C. in the case of polyester fibers), and the yarn coming from this heater 6 is air-cooled to a temperature lower than the second transition point of the yarn (lower than C. in the case of polyamide fibers and lower than C. in the case of polyester fibers). In the twister device 1 of the present invention detailed hereinbelow, the heated yarn is twisted, and then, the yarn is withdrawn from the twister device 1 in the form of a crimped yarn and is wound on a paper spool 12 through an apron type take-up roller 6 and a second guide 11. The twister device 1 hasa turbine blade type high speed rotary member having a twister pin installed therein. Accordingly, compressed air is fed in the direction shown by an arrow 8, the rotary member 17 is rotated at such a high speed as 750,000 to 800,000 r.p.m. to twist and untwist the unprocessed filamentary yarn 3. The compressed air which has done such rotation work is discharged in the reduced pressure state in the direction shown by an arrow 9.

The twister device 1 will now be described in more detail by reference to FIGS. 2 to 4.

This twister device 1 includes a passage 13 for a yarn 3 to be processed in the interior of a hollow shaft and a twister pin 14 disposed in this passage 13. The twister device 1 further comprises a turbine blade type rotary member 17 which is rotated at a high speed in a casing 16 when compressed air is applied onto blades 15 formed to project stepwise on the circumference of the rotary member 17 around the middle portion thereof. An upper lid 18 and a lower lid 19, each having a round hole at the center thereof, are screwed to the upper and lower faces of the casing 16, respectively. An upper air bearing 20 is screwed to the lower face of the upper lid 18, and a lower air bearing 21 is screwed to the upper face of the lower lid 19.

Compressed air is introduced from an introduction opening 22 disposed on the casing 16, and it is projected to the blades 15 of the rotary member 17 from a nozzle 23. Then, the air is withdrawn outside the casing 16 through a discharge air passage 24. Air bearings 20 and 21 have functions of introducing compressed air from an introduction passage 25 and projecting it to the rotary member 17 at both the ends of the stepped portion of the hollow shaft thereof, thus supporting the rotary member 17 in the floating state.

As is seen from FIG. 3, a propelling force owing to the difference of the tension between the unprocessed yarn side 3 and the crimped yarn side is applied in the direction of advance of the filamentary yarn (in the downward direction in FIG. 3). In the twister device 1 shown in the drawings, the rotary member 17 is composed of a magnetic material and both the upper air bearing 20 and the lower air bearing 21 are composed of a non-magnetic substance, and a magnet 30 is disposed on the upper face of the lower air bearing 21 to have a close contact therewith, so that the above propelling force applied to the rotary member 17 is reduced by the repulsive magnetic force generated between the confronting surfaces of the magnet 30 and rotary member 17 of the same polarity. On the upper lid 18 disposed on the yarn-introducing side of the casing 16, a plurality of air-projecting holes 27 are mounted to cool the heated yarn to a temperature lower than the second transition point thereof, and these holes 27 are connected to the above-mentioned discharge air passage 24 through a passage 28 (see FIG. 2), so that the discharge air is utilized for cooling the heated yarn. Further, a cooling cylinder 31 is dismountably fitted on the upper lid 18.

In the twister device 1 having the foregoing structure, when compressed air is introduced at the introduction opening 22 and it is projected to the blades of the rotary member 17 from the nozzle 23, the rotary member 17 is rotated at a high speed, and the unprocessed filamentary yarn 3 is crimped by the twister pin 14 in the above-mentioned manner and it is taken up in the form of a crimped yarn 10 by the apron type take up roller 6. A part of the discharge air which has imparted an energy to the rotary member 17 is introduced to the air-projecting opening 27 mounted on the upper lid 18 from the midway of the discharge air passage 24 through the passage 28, and it is projected to the heated unprocessed yarn 3 from the opening 27 as shown by an arrow 29, whereby the temperature of the unprocessed yarn 3 is lowered below the second transition point of the yarn. Separately, compressed air is introduced into the air bearings and 21 through the air-introducing passage 2, and the compressed air is projected to the stepped portion of the rotary member 17 from the projecting holes 26 mounted on respective bearings 20 and 21, so that the rotary member is supported in the floating state and it can be rotated at a high speed conveniently. During the crimping processing operation, the propelling force should inevitably be generated in the direction of advance of the filamentary yarn owing to the difference of the tension imposed on yarn between the introduction side and the discharge side. In the twister device of the present invention, as is shown in FIG. 3, the rotary member 17 is composed of a magnetic material and a magnet 30 is closely attached to the upper face of the lower bearing 21. Since the rotary member 17 and magnet 30 have the same polarity, a magnetic repulsive force is generated between the confronting surfaces of the rotary member 17 and magnet 30 and the above-mentioned propelling force is reduced by the quantity corresponding to this repulsive force.

An example of the processing operation using the twister device of the present invention will now be described in detail.

When 40-denier yarns of polyamide filaments are processed by employing the twister device of the present invention, the rotation number of the rotary member 17 is 750,000 rpm, the twist number is 4,000 T/m, the overfeed ratio is 2% and the yarn speed is 187 m/min. Thus, the processing speed attained is about 2 times as high as attainable in the conventional method using a spindle. In this case, the deviation of the rotation number among the twister device units is within a range of i 1%, and the pressure of the compressed air is 3 kg/cm at the bearing portion and 3.5 kg/cm at the nozzle for projecting compressed air to blades 15 of the rotary member 17. The amount consumed of the compressed air is 0.025 Nm lmin.

Data obtained in an example for preparing fancy crimp yarns are shown in Table 1.

Table 1 As is apparent from the data shown in Table l, the number of twists per meter changes in proportion to the pressure of projected air. Therefore, fancy crimp yarns rich in variations of the appearance can easily be obtained by adjusting appropriately the rate of the change of the pressure of compressed air and changing appropriately intervals of applying compressed air of a certain pressure.

As is seen from the foregoing description, the twister device of the present invention comprises a turbine blade rotary member including a twister pin for an introduced filamentary yarn disposed in the interior of a hollow shaft, and blades projected stepwise on the circumference at the middle portion thereof and a casing disposed to enclose the outer periphery of the rotary member, wherein a gas-projecting opening for supplying a compressed gas to the blades of the rotary member and imparting a rotating power to the rotary member and another gas-projecting opening for supplying a compressed gas to both the ends of the stepped portion of the hollow shaft and supporting the rotary member in the floating state are mounted in the interior of the casing separately from each other. By virtue of the above characteristic features, in the twister device of the present invention, the projecting gas stream for attaining the rotating function and the projected gas stream for attaining the bearing function can be controlled independently from each other while grasping precisely these streams based on numerical values. Accordingly, conditions of the bearing function and rotation number can optionally be chosen depending on the size of the unprocessed yarn, and the quality of the product yarn can be precisely grasped and controlled. This is one of advantages attained by the presentinvention. Further, a sufficient bearing capacity can be ensured depending on the mass of the rotary member and the properties of the yarn by the projected gas stream applied independently to both the ends of the stepped portion of the hollow shaft. Therefore, a high speed operation can be maintained stably, and by the synergistic effect of this gas stream and the separately applied gas stream for attaining the rotating function, it is made possible to heighten the low constant speed operation rotation number to a level exceeding 800,000 rpm. and hence, the rate of manufacturing crimped yarns can be greatly enhanced.

Further, when the projected gas stream for attaining the bearing function and the projected gas stream for attaining the rotating function are supplied separately and independently in the above-mentioned manner, if different compressors are chosen for respective projected gas streams and influences of pulsating flows accompanying the gas streams are scattered and thus reduced, the stability at the high rotation operation can be enhanced and maintained at an enhanced level. Accordingly, in the twister device of the present invention, the bearing member is not worn and its life can be prolonged. Further, no varition in the rotation number is brought about because the rotary member is not worn by friction. Accordingly, desired crimpled yarns can be always be obtained assuredly.

In case compressed-air is applied for rotating the rotary member, since the Mach number is maintained 'at l.5 2, the temperature of the air at the time when it impinges to the rotary member is reduced to about C. at the highest by adiabatic expansion and the air exerts the cooling action on the rotary member. Accordingly, the twister pin is always kept in the cooled state and it exerts the cooling effect on the filamentary yarn before the untwisting, and the crimp fastness and bulkiness are improved in the resulting crimped yarns. Further, in the twister device of the present invention, since the rotary member is driven by compressed air and the bearing member is kept in the completely floating state by the air bearing, the discontinuous operation of the rotary member can be performed very easily. Accordingly, the crimp form can be partially changed if desired and hence, so called fancy crimp yarns can readily be prepared.

A particular advantage of the present invention over the false twisting system using a spindle is that the abrupt increase of the rotation number such as seen at the start of operation of the spindle can easily be eliminated and frequency of yarn breaks at the time of taking up yarn onto the twister can be greatly reduced by very simple means. Moreover, since a gas is used as a power source and a bearing for the rotary member, automation of the driving and stopping operations can be accomplished at a low cost. Still in addition, in the irequired of the false twister per se as in the conventional spindle system and hence, the equipment cost can be greatly reduced in the present invention.

In the embodiment of the twister device of the present invention where a plurality of gas-projecting openings opened with an inclination with respect to the filamentary yarn are disposed on the yarn-introducing side, not only the discharge gas which has imparted a rotation energy to the rotary member, as in the foregoing example, but also a compressed air fed from a different projected gas stream source can be supplied to these gas-projecting openings, because they are arranged in the interior of the casing. Accordingly, it is possible to accelerate cooling of the heated yarn introduced into the twisting zone by possitively blowing a compressed gas to the filamentary yarn and to thereby enhance the setting effect. Simultaneously, it is possible to shorten the cleaning zone in the crimper device by such positive application of a compressed gas. in addition, since a plurality of such gas-projecting openings are opened with an inclination toward the yarn-introducing side of the casing, namely in the direction contrary to the yarn-running direction, the projected gas streams act in the direction reducing the propelling force applied on the yarn in the running direction and these projected gas streams have an effect of competing with the propellingforce.

In the embodiment of the twister device of the present invention where at least one of axial end faces of each of the blades projected stepwise from the hollow shaft is composed of a magnetic material and a magnet having a polarity identical with or different from the polarity of this magnetic material is attached in the interior of the casing at the position confronting said end face to thereby impart to the rotary member a magnetic force acting in the direction opposite to the propelling force imposed in the direction of advance of the yarn, since magnetic materials are disposed on the axial end face of the blade projected stepwise from the hollow shaft and at the confronting position in the interior of the casing, a relatively great magnetic force to be applied to the rotary member can easily be obtained, and this magnetic force is well-balanced with high speed rotation of the rotary member and hence, stable rotation can always be ensured in the rotary member and undesired contact can be prevented between the rotary member and air bearing.

As is apparent from the foregoing description, the structure of the twister device of the present invention is very simple and it exerts its functions assuredly. Therefore, the effects attained by the present invention can be greatly amplified. ln embodiments shown in the drawings, the central position of the twister pin is in agreement with the central position of the rotary member, but in the present invention it is permissible to adopt a modification where a twister pin is located at the position deviated from the center of a filamentary yarn to be crimped by a distance corresponding to at least the radius of the narrowest portion of the twister pin, so that the centrifugal force imposed on the yarn by high speed rotation can be reduced and ballooning of the yarn can be minimized. Further, as regards means for reducing the propelling force imposed on the rotary member in the direction of advance of the yarn, which is generated owing to the difference of the tension of the yarn between the introduction side and the discharge side, there are two modes; one in which the magnetic materials are so disposed that the magnetic materials of the same polarity repulse each other and the other in which the magnetic materials are so disposed that the magnetic materials differing in the polarity attract each other.

What is claimed is:

l. A twister device for producing crimped yarns coinprising a turbine blade rotary member including a twister pin for an introduced filamentary yarn disposed in the interior of a hollow shaft thereof and blades projected stepwise on the circumference at the middle portion thereof and a casing disposed to enclose the outer periphery of the rotary member, wherein a gasprojecting opening for supplying a compressed gas to the blades of the rotary member and imparting a rotating power to the rotary member and another gasprojecting opening for supplying a compressed gas to both the ends of the stepped portion of the hollow shaft and supporting the rotary member in the floating state are mounted in the interior of the casing separately from each other, and further including a plurality of gas-projecting openings opened with an inclination with respect to the filamentary yarn to be crimped provided on the yarn introducing side of the casing.

2. A twister device for producing crimped yarns comprising a turbine blade rotary member including a twister pin for an introduced filamentary yarn disposed in the interior of a hollow shaft thereof and blades projected stepwise on the circumference at the middle portion thereof and a casing disposed to enclose the outer periphery of the rotary member, wherein a gasprojecting opening for supplying a compressed gas to the blades of the rotary member and imparting a rotating power to the rotary member and another gasprojecting opening for supplying a compressed gas to both the ends of the stepped portion of the hollow shaft and supporting the rotary member in the floating state are mounted in the interior of the casing separately from each other, and wherein at least one of the axial faces of each of the blades projected from the hollow shaft is composed of a magnetic material and a magnet having a polarity identical with or different from the polarity of said magnetic material is disposed in the interior of the casing at the position confronting said end face, so that a magnetic force acting in the direction opposite to the propelling force imposed in the direction of advance of the filamentary yarn is imparted to the rotary member.

3. A twister device for producing crimped yarns comprising a rotary member having an opening therethrough on the axis of rotation thereof for receiving a yarn passing therethrough on the axis of rotation of the rotary member, means operably associated with the rotary member for crimping the yarn as it is passed through the opening in the rotary member and means for projecting gas toward the axis of rotation of the rotary member and toward the filamentary yarn and away from the rotating member operably associated with and adjacent to the end of the opening in the rotary member into which the yarn is passed to be crimped.

4. Structure as set forth in claim 3 wherein the rotary member is supported in air bearings in a fixed member and further including magnetic means provided between the rotary member and fixed member for biasing the rotary member axially of the axis of rotation thereof.

5. A twister device for producing crimped yarns comprising a rotary member having an axis of rotation, a fixed member, bearing means for supporting the rotary member on the fixed member for rotation about the axis of rotation of the rotary member and magnetic means operable between the rotary member and fixed member for biasing the rotary member in at least one direction along its axis of rotation. 

1. A twister device for producing crimped yarns comprising a turbine blade rotary member including a twister pin for an introduced filamentary yarn disposed in the interior of a hollow shaft thereof and blades projected stepwise on the circumference at the middle portion thereof and a casing disposed to enclose the outer periphery of the rotary member, wherein a gasprojecting opening for supplying a compressed gas to the blades of the rotary member and imparting a rotating power to the rotary member and another gas-projecting opening for supplying a compressed gas to both the ends of the stepped portion of the hollow shaft and supporting the rotary member in the floating state are mounted in the interior of the casing separately from each other, and further including a plurality of gas-projecting openings opened with an inclination with respect to the filamentary yarn to be crimped provided on the yarn introducing side of the casing.
 2. A twister device for producing crimped yarns comprising a turbine blade rotary member including a twister pin for an introduced filamentary yarn disposed in the interior of a hollow shaft thereof and blades projected stepwise on the circumference at the middle portion thereof and a casing disposed to enclose the outer periphery of the rotary member, wherein a gas-projecting opening for supplying a compressed gas to the blades of the rotary member and imparting a rotating power to the rotary member and another gas-projecting opening for supplying a compressed gas to both the ends of the stepped portion of the hollow shaft and supporting the rotary member in the floating state are mounted in the interior of the casing separately from each other, and wherein at least one of the axial faces of each of the blades projected from the hollow shaft is composed of a magnetic material and a magnet having a polarity identical with or different from the polarity of said magnetic material is disposed in the interior of the casing at the position confronting said end face, so that a magnetic force acTing in the direction opposite to the propelling force imposed in the direction of advance of the filamentary yarn is imparted to the rotary member.
 3. A twister device for producing crimped yarns comprising a rotary member having an opening therethrough on the axis of rotation thereof for receiving a yarn passing therethrough on the axis of rotation of the rotary member, means operably associated with the rotary member for crimping the yarn as it is passed through the opening in the rotary member and means for projecting gas toward the axis of rotation of the rotary member and toward the filamentary yarn and away from the rotating member operably associated with and adjacent to the end of the opening in the rotary member into which the yarn is passed to be crimped.
 4. Structure as set forth in claim 3 wherein the rotary member is supported in air bearings in a fixed member and further including magnetic means provided between the rotary member and fixed member for biasing the rotary member axially of the axis of rotation thereof.
 5. A twister device for producing crimped yarns comprising a rotary member having an axis of rotation, a fixed member, bearing means for supporting the rotary member on the fixed member for rotation about the axis of rotation of the rotary member and magnetic means operable between the rotary member and fixed member for biasing the rotary member in at least one direction along its axis of rotation. 